A 60‐year‐old woman has a diagnosis of metastatic breast cancer. You see her in clinic and she tells you that she is feeling more unwell. She describes to you that she feels nauseous, she is constipated and drinking more water that usual. On examination her BP is 110/90 mmHg, pulse 100 beats/min and saturations 99% on room air. She looks clinically dehydrated with reduced skin turgor and dry mucus membranes. Her chest was clear, abdomen was mildly tender but with no rebound or guarding. Blood tests showed:

Fig. 0004.